2.2.21a3
	crystalball from NIST is relicensed under the GNU GPL version 3 license
	by the main developer who does not work at NIST anymore
	the program is renamed crystalballplus

2.2.21a2
	bug-fix: I forgot to update the README file with the public
	domain notice

2.2.21a
	new: changing license. NIST requires that this software be placed in
	the public domain. The license for ALL previous versions should be
	considered void.
	
2.2.20a
	enhance: zone axis and angle comparison functions have been merged
	and made much faster

2.2.18a
	bug fixed: potentially good values were excluded
	new: MillerPlane can be iterated
	new: functions 'difference', 'symmetryc_difference', 'union'
	     that work with sets of lists

2.2.16a
	new configurable parameter in GUI: "report non-matching values"
	
2.2.15a
	faster zone axis grouping algorithm
	test module

2.2.12a
	better text executable (also, must use -GUI option to start GUI)
	improved grouping algorithm
	use of xrange instead of range throughout the code

2.2.11a
	report generation: files with no matches can be optionally listed
	report generation: files are listed in alphabetical order
	bug fixed: fixed bug for which the angle report was empty when
	multiple input files were used
	
2.2.10a
	GUI configuration: added check angle ('any' or 'all')
	GUI progressbar added

2.2.9a
	new GUI with configuration menu and better controls
	0-rank array bug fixed

2.2.0a
	new matching algorithm, faster and more intelligent.
	KNOWN BUGS: somwhere during the process, a 0-rank array
	containing the MillerPlanes and the spot number is generated.
	
2.1.5a
	new utility function: anglecount.
	
2.1.4a
	bug-fix release.
	Starting from now, I am going to have alpha and beta releases.
	
2.1.3
	Angle report returns the zone axis family

2.1
        Added a simple WxPython GUI.

2.0.1
        New shell application 'crystalball.py'.
        Better report generation.

1.5
	Read crystal structure from text files (custom '.dfg' format).
	Read multiple 'input' and 'reference' files and compare them.
	Generate text reports.
	
0.5
	added OOP functionality: Diffractogram and DiffractogramFile classes
	1st class is a general one; 2nd one allows the user to read the data
	from a text file.
	
0.1
	1st release
	some basic functionalities to read files
	function to compute the angle of intersecting hkl planes
	function to match two sets of data (useful to match spacings
	measured from diffractograms to reference spacings from e.g.
	X-ray diffraction data).

